Design And Optimization Of The Novel Permanent Magnet Assisted External Rotor Switched Reluctance Motor

With the continuous improvement of the cost performance of high-performance permanent magnet materials,the research and application of various novel permanent magnet motors are more and more at home and abroad,and permanent magnet motors are also playing a decisive factor in more and more applications.Based on the above background,the electromagnetic design and structural parameter optimization of Permanent Magnet assisted External Rotor Switched Reluctance Motor(PMa-ERSRM)are studied in this paper.This paper elaborates the theoretical analysis of the external rotor switched reluctance motor assisted by permanent magnet,completes the design of the size parameters of the motor,establishes the equivalent magnetic circuit model,carries on the simulation analysis of the steady state performance of the motor,and finally compares the performance of the external rotor switched reluctance motor assisted by permanent magnet and the ordinary external rotor switched reluctance motor.The concrete work and conclusions of this paper are as follows:(1)Put forward a novel type of permanent magnet structure auxiliary external rotor switched reluctance motor,the stator slot to establish permanent magnet and electric field parallel hybrid excitation method,this paper expounds the structure and working principle of new type motor,completed the size parameters of the motor design,choose the size of the permanent magnet,analyses the working model of permanent magnet and a magnetic,electrical equivalent magnetic circuit model is established and completed the establishment of a new type of motor mathematical model.(2)The influence of parameters of PMa-ERSRM to performance is analyzed,and the optimization variables and objectives.objectives are determined.BBD experiment was used in Desking-Expert to Design and optimize the parameters,and the finite element simulation of PMa-ERSRM was completed in ANSYS Maxwell software.The experimental data were obtained,the structural parameters of PMa-ERSRM were regression fitted,the second-order response surface equation was obtained,and the multi-objective optimization problem and constraint conditions of PMa-ERSRM were determined.(3)In order to reduce torque ripple of PMa-ERSRM,efficiency and average torque,the NSGA-Ⅱ improved algorithm for multi-objective optimization,with the second order response surface equation as fitness function,the optimal approximation solution set is obtained,and by using the fuzzy set theory to Pareto optimal solution selection,get relatively better motor parameters.(4)The static analysis of the new type of permanent magnet assisted external rotor switched reluctance motor is carried out,and its electromagnetic torque,flux linkage,inductance and air gap flux density are analyzed.And compared with the traditional external rotor switched reluctance motor,the results show that the new motor has lower saturation degree,higher average torque and higher motor utilization coefficient.